The contamination of mercury in air, water and soil is increasing with the development of industry. It also induces the risk of mercury in food through food chain. Mercury is found in milk after dairy cow consume feed and water contented high level of mercury. The mercury in milk is paying attention by our consumers. In the present paper, occurrence form, source, harm and surveillance of mercury in milk were reviewed in order to make consumers know more knowledge on mercury in milk.

To transfect histone deacetylases 1(HDAC1)-small interferencing RNA (siRNA) into mouse renal tubular epithelial cells (RTECs) by liposome transfection and to investigate its inhibitory effect on HDAC1.It was transient into RTECs by liposome transfection. Fluorescently labeled siRNA (the FAM-siRNA) to filter the proportion of transfected. Real-time fluorescence quantitative polymerase chain reaction (Real-time PCR) to determine the optimal conditions and testing the various sites(374, 525 and 822)HDAC1-siRNA inhibition effect, MTT method to detect the influence of the HDAC1-siRNA on suppression RTECs proliferation in different time points, and trichostatin A(TSA) disposal group as a test control. Expression of fluorescence and Real-time PCR results showed that 30 pmol siRNA∶1.5 mL Lipofectamine^TM 2000 were optimal transfection conditions and HDAC1-374 had the most obvious interference effect. The MTT testing results of HDAC1-374 and TSA were consistent: HDAC1-siRNA could effectively restrain RTECs proliferation. The test using liposomes transiently transfected siRNA method, successfully inhibition the expression of HDAC1 in RTECs.

In this study, 5 strains of Haemophilus parasuis(Hps)were identified by ‘satellite’ growing test, biochemical and PCR assay. The results showed that aroA gene of the isolated Hps had a high degree of similarity with classical culture strain in the sequence of nucleotide and amino acid sequence, which was between 96.3% to 99.8% and 98.2% to 99.5% respectively. We implemented two program of triplex PCR assay, one group was used to detect simultaneously infections of Hps, PCV2 and PPV, the other group was developed to detect the PCV2, PPV and PRV. The sensitivity tests indicated that the triplex PCR assay may be used for detecting Hps, PPV, PRV and PCV2 of 10⁵ dilute strength; the DNA minimun detectable quantity of Hps, PPV, PRV, PCV2 was 12, 16, 7.6 and 6.3 pg respectively.

According to the env and LTR gene of avian leukosis virus subgroup J, 4 and 5 short hairpin RNAs (shRNAs) targeting their conserved sequences were designed systhessised and cloned into pSilencer 4.1 vector respectively. The recombinant plasmids were transfected into DF-1 cell and infected with 10³ TCID₅₀ ALV-J at 6 hours post-transfection, the efficiency of RNA interfering was assayed by Real-time RT-PCR .The results revealed that the recombinant plasmids of pSi4.1-env inhibited virus growth by 18.15% to 63.43% and pSi4.1-LTR by 19.37% to 45.41% compared to negative control.

To select the best stable reference genes and investigate the developmental expression patterns of AKT gene in sheep fetal muscle. Quantitative RT-PCR was conducted for B2M, GAPDH, RPLPO, RPS18 and SDHC and also applied to investigate AKT mRNA expression at the gestation of 70 d, 85 d, 100 d, 120 d and 135 d in longissimus dorsi muscle of Texel and Ujumuqin sheep. The five reference genes of expression stability were analyzed by the GeNorm software, and the result showed that RPS18＞RPLPO＞SDHC＞B2M＞YWHAB. Furthermore, SDHC, RPLPO and RPS18 were identified as the most stable reference genes in the present study. In all the five stages, the expression patterns of AKT were dissimilar in the two sheep breeds. Strikingly, at the gestation of 85 d and 120 d, the expression of AKT reached their peak values in Texel,in contrast, in Ujumuqin it was at 100 d. These findings were consistent with our previous study which reflected the histological characteristics during the second half of gestation in the two sheep breeds, and this further verify that the surges in myofiber hyperplasia occurred at 85 d and 120 d in Texel sheep, whereas a unique proliferative surge appeared at 100 d in Ujumqin sheep. The results indicated that the transcript levels of AKT gene exhibited specific developmental expression changes between Texel and Ujumuqin sheep, and provided some data for further study on the effect of AKT gene.

The surface layers protein (SLP) is a major composition of the bacterial outermost envelope with highly ordered ultrastructure. The Lactobacillus brevis which isolated from Mongolian traditional dairy products were used as materials in this study. The S-layer proteins from several Lactobacillus were detected by SDS-PAGE and slp gene was cloned by PCR and then analyzed the slp gene sequence of Lactobacillus breris. The results showed that the protein sample of Lactobacillus breris showed target band about 44 to 55 ku which had the same size range of SLP that had been reported,and slp gene about 1300 bp was amplified by PCR method. The DNAStar software found that the protein had recently kinship and genetic distance with L.gallinarum strain (GenBank:AY597266.1) and was similar to other Lactobacillus spp. The theoretical size of S-layer protein was about 47 ku released by the Genetyx software and had significant feature of outer membrane proteins. This layed foundation for genetic modification and other research work.

Establish a diplex PCR assay was to detect porcine parvovirus (PPV) and porcine encephalo myocarditis virus (EMCV) simultaneously.According to PPV VP2 gene sequences and EMCV 3D gene sequences in GenBank, special primers of PPV and EMCV were designed by Premier 5.0 software. Trough optimizing the reaction conditions, a diplex PCR assay,which could detect PPV and EMCV simultaneously,was established. The sensitivity of PPV and EMCV were 7.62 and 1.22×10^-1 pg/μL respectively. Clinical tests of 36 samples showed that the diplex PCR detection assay was sensitive, specific, and suitable for clinical application.

Two monoclonal antibodies against rabies virus glycoprotein were produced by immunization with rabies virus strain BD06 in BALB/c mice. Splenocytes from the immunized mice were fused with SP2/0 mouse myeloma cells. After fusion, antibodies in the supernatant of the hybrid cells were respectively detected by ELISA and FAVN tests. Two hybrid cells secreting antibody binding to rabies virus, i.e. 6F12 and 1B12 strains, were analyzed by Western blotting and FAT methods. Results showed that conformational and linear epitopes of the glycoprotein were repectively recognized by neutralizing monoclonal antibody 6F12 and 1B12.

According to the yeast system codon partial tropism, modifying the nucleotide sequence of the mature protein co-don,this research used the Pichia pastorios secretion expression vectors pPICZαC to express canine interferon alpha maturedon,this research used the Pichia pastorios secretion expression vectors pPICZαC to express canine interferon alpha mature protein. CaIFN-α was measured by cytopathic effects with Vero-VSV system,the same methods to measure inhibitory effect on PRV and CDV. The results showed that the canine IFN-α got a high expression in yeast. SDS-PAGE showed the protein got 24 ku, larger than the expected size. The CaIFN-α had species specificity, it had a high antiviral activity to PRV on vero cell, reached 3.6 × 10⁷ U/L, and also had a good inhibition to CDV. Its expression got 58 mg/L. The study provided the base for further study of CaIFN-α activity and its clinical application.

To lay the foundation for investigating the role of Arkadia expression vector in mouse aristolochic acid nephropathy (AAN), we optimized the transfection conditions of ubiquitination enzyme Arkadia plasmid expression vector pGPU6/GFP/Neo in mice renal tubular epithelial cells (RTECs). Mice RTECs were taken for transfection object, and liposome Lipofectamine^TM 2000 for transfection medium, we detected the Arkadia mRNA expressions differences and the affects of cell activity under the different ratios conditions of plasmid and liposome by Real-time PCR and CCK-8 assay; at the same time, the differences of Arkadia mRNA expressions silence under the different transfection time conditions by Real-time PCR.The results showed that transfection efficiency of Arkadia-pGPU6/GFP/Neo vector displayed dose and time dependents. When the ratio of plasmid DNA∶Lipofectamine^TM 2000 was 0.66 μg∶2 μL, and the transfection time was 24 h, Arkadia mRNA expression inhibition was very obvious and the cytotoxicity was the lowest.Lastly, we determined the best transfection condition of Arkadia-pGPU6/GFP/Neo vector.

Porcine parvovirus(PPV), pseudorabies virus(PRV) and porcine circovirus type 2(PCV2) were three main viral pathogens of porcine reproduction barrier diseases. To identify and differentiate rapidly the cause(s) of clinical diseases, a multiple PCR/RT-PCR assay was developed. Based on the similarity of the viral sequences deposited in the GenBank database, the VP2 gene of PPV, the gD gene of PRV and the ORF2 gene of PCV2 were selected as the diagnostic targets. By using three pairs of virus-specific primers, three PCR/RT-PCR assay were established to amplify the conservative regions of the three viruses, respectively. Consequently, a multiplex PCR/RT-PCR method to detect the three viruses in one tube was developed. The multiple PCR/RT-PCR system would amplify a 313 bp fragment for PPV, a 217 bp for PRV and a 447 bp for PCV2 simultaneously or separately in the samples, depending on its infection status. By comparison, the test proved that the multiplex PCR method being 100% coincidence with the single PCR, and it could be used for this three virus detection and differential diagnosis. 211 samples of pigs collected from 10 nosopoietic pig farms and outpatient cases were detected with the multiplex PCR assay established, the result showed that the positive rate of 42 positive PPV was 19.91%, the positive rate of 26 positive PRV was 12.32% and the positive rate of 56 positive PCV2 was 26.54%, more than, the mixed infection rate of 25 two kinds of mixed infection was 11.85%. It proved that the pigs had been infected by these three epidemics in Shanxi.

In this study, we reported a new method of pyrosequencing-based sequence analysis to detect Pseudomonas aeruginosa,which was a rapid simple method. After extracting DNA from cultured cells, Pseudomonas aeruginosa were preliminarily determined by PCR on a specific sequence of the exotoxin A gene which containing conserved fragment respectively. Then the results obtained by PCR were further validated via the pyrosequencing method, and the sequences were demonstrated to specific of Pseudomonas aeruginosa. By conventional sequencing, the sequences results were 100% in agreement with pyrosequencing. Comparing the sequence got by pyrosequencing with the known sequence, you would find the sequence was Pseudomonas aeruginosa.This method was accurate,fast,and could be used efficiently for identifying the Pseudomonas aeruginosa.

A strain of goose parvovirus (SS/10) was isolated from gosling hepar and biological characteristics of the virus were studied.The result indicated that the ELD₅₀ to muscovy duck embryos was 10^-4.6/0.3 mL and no goslings were dead after inoculation,but pathological change by tissue section was evident. Sequence analysis showed that the homology with DY strain was lower than other reference strains in VP1,VP2 and VP3 genes respectively and there was no difference in NS1 and NS2 genes; VP3 gene belonged to a branch with 82-0321V,VG32/1 and B strains published in GenBank. It had closest genetic relationship with 82-0321V and farthest genetic relationship with muscovy duck parvovirus GD strain. Glycosylation sites analysis showed that VP3 had one less glycosylation site than B.

To identicate Listeria monocytogenes isolates from North of Xingjiang sheep, 8 Listeria monocytogenes isolates of 30 Listeria spps isolates, isolated from diseasing sheep, healthy sheep, environment and bird droppings at sheep farms in epidemic areas of Listeriosis were identified and serotyped by multipelx PCR method. The results showed that among 4 strains of Listeria isolated from diseasing sheep, 3 strains were serovar 1/2a or 4b of Listeria monocytogenes, and 1 strain was not Listeria monocytogenes; 5 strains from healthy sheep serovar were 1/2a;3 strains isolated from water, 2 strains from crow droppings and 16 strains of Listeria monocytogenes isolated from healthy sheep were not isolates of Listeria monocytogenes. The study suggested that there was correlativity among serovars of strains of Listeria monocygenes from diseasing sheep, healthy sheep and reference strain Listeria monocytogenes.

To identicate Listeria monocytogenes isolates from North of Xingjiang sheep, 8 Listeria monocytogenes isolates of 30 Listeria spps isolates, isolated from diseasing sheep, healthy sheep, environment and bird droppings at sheep farms in epidemic areas of Listeriosis were identified and serotyped by multipelx PCR method. The results showed that among 4 strains of Listeria isolated from diseasing sheep, 3 strains were serovar 1/2a or 4b of Listeria monocytogenes, and 1 strain was not Listeria monocytogenes; 5 strains from healthy sheep serovar were 1/2a;3 strains isolated from water, 2 strains from crow droppings and 16 strains of Listeria monocytogenes isolated from healthy sheep were not isolates of Listeria monocytogenes. The study suggested that there was correlativity among serovars of strains of Listeria monocygenes from diseasing sheep, healthy sheep and reference strain Listeria monocytogenes.

Gram negative bacilli was isolated from lung of sick pig in Large-scale pig farm, the bacilli was identified as Haemophilus parasuis by physiological and biochemical identification, PCR identification and 16S rRNA gene nucleotide BLAST. Antibiotics sensitivity test showed that the isolation strain was high sensitive to erythrocin, chloromycetin, cephalothin, etc. Low sensitive to gentamycin, ofloxacin, noroxin, and resistant to sulfamethoxazole. The analysis of 16S rRNA showed that the 16S rRNA sequence homology between the isolated strain and reference strain Haemophilus parasuis AB078973(GenBank accession number) was 100%. Phylogenetic tree of 16S rRNA showed that the isolated strain was situated on the same branch with 3 serotype 5 reference strains AB078972,AB078973 and AB078974, and the nucleotide homology between the isolated strain and the 3 reference train was 99.0% to 99.4%. Therefore,the isolated strain was identified as Haemophilus parasuis serotype 5. Pathogenicity test showed that the isolated strain was highly pathogenic to laboratory mice. The isolated Haemophilus parasuis strain was named YN-1 strain.

According to IL-15 gene sequence of Mus musculus available in GenBank database, specific primers were designed and synthesized. Using reverse transcription-polymerase chain reaction (RT-PCR) method, mature IL-15 sequence was amplified from the spleen cells of Kunming (KM) mice stimulated for 72 h by Toxoplasma gondii RH strain, then cloned into pMD18-T vector and transformed into the competent Escherichia coli JM109 for obtaining the positive clone and sequenced. Sequencing analysis revealed that the length of mature IL-15 of KM mice was 345 bp, encoding 114 amino acids. The results of sequence alignment and genetic evolution analysis showed that the KM mice mature IL-15 sequence was the closest to Norvegicus rattus, and the homologies of nucleotide and amino acid sequence were 94.2% and 95.5% respectively. Sequence similarity between the KM mice mature IL-15 sequence and that of Cavia porcellus, human, primates, Oryctolagus cuniculus, dog, cat, Bos taurus, Sus scrofa etc., and the nucleotide homology ranged between 71.2% to 78.8%, and the amino acid homology was 69.5% to 74.7%. The successful cloning of KM mouse IL-15 gene provided foundation for further studies of its functions and immune stimulating effects.

To establish a rapid differential diagnosis method of porcine reproductive and respiratory syndrome virus (PRRSV) classic and variant strains, a pair of primers corresponding to the highly conserved regions of Nsp2 gene of PRRSV genome were synthesized according to the sequences of PRRSV on GenBank, a RT-PCR method for detection and differentiation of classical and variant PRRSV was established. A fragment of 549 and 459 bp was amplified from genomic RNA of classical or high-pathogenic PRRSV respectively, no specific products were achieved after differentiating detection of porcine originated viral pathogens including HCV, JEV, PEDV, TGEV, PRV, PCV2 and PPV. The RT-PCR could detect 1 pg RNA of classical and 0.1 pg RNA of variant PRRSV respectively. The established RT-PCR method had good specificity, sensitivity, repeatability, could accurately and quickly identify the classical and variant PRRSV, it provided a kind of efficient, rapid, specific and sensitive detection method for clinical diagnosis, disease detection and molecular epidemiology of material such as porcine reproductive and respiratory syndrome virus.

According to ITS gene sequence of Theileria sergenti in GenBank (AY661522.1), a pair of specific primers was designed and synthesized using Primer Premier 5.0 and Oligo 6.31.Using T. sergenti DNA as templates, PCR method of T.sergenti was established. 1020 bp fragments were amplified. The fragments shared 98% homology with the reference sequence. The established PCR method showed no cross reaction with Mycoplasma suis, Neospora caninum and Toxoplasma gondii RH strain. The minimum detectable DNA amount was 1.5 pg/μL. Sixty clinical samples were detected by PCR method and microscopic examination of Giemsa-stained blood smears. The results showed that the PCR method was sensitive and specific. It was suitable for the detection of T. sergenti.

According to ITS gene sequence of Theileria sergenti in GenBank (AY661522.1), a pair of specific primers was designed and synthesized using Primer Premier 5.0 and Oligo 6.31.Using T. sergenti DNA as templates, PCR method of T.sergenti was established. 1020 bp fragments were amplified. The fragments shared 98% homology with the reference sequence. The established PCR method showed no cross reaction with Mycoplasma suis, Neospora caninum and Toxoplasma gondii RH strain. The minimum detectable DNA amount was 1.5 pg/μL. Sixty clinical samples were detected by PCR method and microscopic examination of Giemsa-stained blood smears. The results showed that the PCR method was sensitive and specific. It was suitable for the detection of T. sergenti.

The paper reviews the latest research advances of colloid gold immunofiltration assay and colloid gold immunochromatography,as representatives of nano-colloidal gold labeling technique,in bovine diseases,analyzes and predicts its application prospect to provide references for the further research and application of this technology in quarantine of bovine diseases.

Designing and synthesizying one pair of primers according to the published PCV2 genome sequence, a fragment of about 480 bp long was amplified by RT-PCR technique with specific primers. Then the target fragment was directionally cloned into pGEX-6p-1 vector. After identifying with enzyme cut and sequencing, the recombinant plasmid was transformed into E. coli BL21(DE3). The recombinant Cap protein was expressed in inclusion body form after induction with IPTG. After denaturation, renaturation of recombinant protein by affinity chromatography purification, purification of the recombinant protein concentration was 0.396 mg/mL. Western blotting and indirect ELISA testing showed that the purified recombinant protein retained better antigenicity and specificity.

The aim of the experiment is to study two kinds of additives in the same formula, on the growth and development of beef cattle tissues and organs of influence. Thirty heads Xinjiang brown were randomly divided into three groups, patients with the control group has the same food.TestⅠboars group adding 1% compound additive of beef cattle fattening feed.Test Ⅱ boars group adding 0.2% powerfeel. The experiment for beef bones and organs organization of growth, production method and meat performance make analysis. The results showed that test Ⅰ group, the test Ⅱ group compared with the control, at the waist, hip wide wide angle, blood weight were significant difference (P<0.05). In addition, in the fattening increase heavy, trunks, puremeat, superior quality meat sales gains profit the revaluation were 42.7,130.6,142.22,141.6 and -15.8,38.2,76.1,149.7 yuan.Therefore, two kinds of additives on the growth and development of the animal, muscle, bone and adipose tissue had certain regulation function. Powerfeel had increased beef fat metabolism, reduced body fat effect.It could be used as a safe, efficient feed additives used in the production of beef cattle fattening.

This study was designed to explore the impact of different L-arginine levels on the pregnant Rex rabbit serum Th1 and Th2 cytokines and provided a theoretical basis for the development of pregnancy Rex rabbit feed. Seventy-two estrus Rex rabbits were randomly divided into six groups: the group 1 to the group 6. The levels of IL-2, IFN-γ and IL-4 were measured by ELISA at 10 days, 20 days and 30 days in pregnancy serum. The results showed that the levels of IL-2 with the groups 4,5,6 were significantly lower than the groups 1,2,3(P＜0.05) in 10 days of pregnancy; the levels of IL-2 with the groups 3,4,5,6 were significantly lower than the groups 1,2 (P＜0.05) in pregnancy 20 days and 30 days. While the levels of IL-4 with the groups 3,4,5,6 were significantly higher than the groups 1,2 (P＜0.05) in pregnancy 10 days and 30 days,the levels of IL-4 with the groups 2,3,4,5,6 were significantly higher than the group 1 (P＜0.05) in pregnancy 20 days. The concentration of IFN-γ significantly decreased when the addition of Arg was in the 0.15%, and no longer significantly changed with the increasing of Arg. Therefore, 0.3% was the optimal added amount for pregnancy Rex rabbit.

This study was designed to investigate the effects of supplementation of composite probiotics on production performance of layer breeders. A flocks of 384,15-week-age Hy-line brown parents were randomly divided into four groups,each group was assigned 4 replications and 24 layers per replication. Control group was fed basal diet, test 1, 2, 3 groups were added 50,100,200 g/t of composite probioticsin in the basal diet. The results showed that the test 3 group of average eggs weight was significantly higher than the control group (P＜0.05), but open day age later than the control group. In 27 to 30-week-age, the test 2 group greatly improved the laying ratio and reduced the ratio of feed to eggs (P＜0.05), but the test 3 group of the laying ratio was significantly lower (P＜0.05) and the ratio of feed to eggs was higher (P＞0.05). The reproductive performance index had no significant difference in each group. Therefore, feed composite probiotics could improve the chicken egg early production performance, the amount of 100 g/t of composite probiotics was appropriate for the experiment.

Montmorillonite(MMT) was a kind of laminated structure, composed of the aluminosilicate structure of Si, Al and a small amount of Fe, Ca, Mg and so on, derived from a natural bentonite, and as a new feed additive in livestock production. The author mainly introduced the MMT of physical and chemical properties, the mechanism and application in ruminant production.

Milk urea nitrogen (MUN) is the concentration of urea nitrogen in milk which is an major indicator meaning efficiency of utilization of dietary crude protein .Thus measuring and using MUN is a way to evaluate whether the diet formulation is suitable or not and whether the feeding program is reasonable or not. This paper reviewed the generation mechanism of MUN, the monitoring methods and its affected factors. It also analysed some current problems and predicted its future development. In a word, it is quite useful for the application of MUN to predict ruminant nutrient requirements and scientific diet formulation.

To study the effects of Chaizhukangjisan on growth performance and the levels of stress related hormones of serum in early-weanling piglets, 48 'Duroc×Landrace×Yorkshine’ crossbred early-weanling piglets in (28±2) day age were randomly divided into 4 treatments of 12 piglets each, with three replicates in each group and 4 piglets in each replicate, and fed with basal diet, basal diet plus 1%,2% and 3% Chaizhukangjisan respectively. The experiment lasted for 28 d. The results showed that adding 2% or 3% Chaizhukangjisan could significantly improve the average daily gain and the average daily feed intake of weanling piglets (P＜0.05),significantly decrease the ratio of feed to gain (P＜0.05) and post weanling diarrhea rates(P＜0.01),significantly decrease the level of serum COR in the age of 35 and 56 d, and significantly improve the levels of Serum GH, INS, T₄ and GAS in the age of 35 and 56d. Chaizhukangjisan could efficiently relieve the weanling stress on piglets. In production practice, adding 2% Chaizhukangjisan in basal diet could obtain the best effect.

An experiment was carried out with a total of 280 1-day-old commercial broilers to investigate the effects of different dietary microecological preparation source and level on growth performance. Birds were randomly assigned by bodyweight to one of 7 treatments (five pen replicates of eight chicks each). The test design for earlier stage (1 to 21 d) and later stage (22 to 42 d), and all groups shared one control group. The results showed that dietary microecological preparation significantly affected (P＜0.05) the ADFI and ADG, but no differences among microecological preparation sources in above indices during 1 to 21 d (P＞0.05). During 22 to 42 d, compared with the control group, ADG and F/G was significantly affected by the microecological preparationⅠand Ⅱ (P＜0.05), ADG increased linearly (P＜0.05) and F/G significantly decreased as dietary microecological preparation level increased (P＜0.05). For the whole stage(1 to 42 d), microecological preparation significantly affected (P＜0.05) the ADG and F/G, ADG increased linearly (P＜0.05) and F/G decreased linearly (P＜0.05) as microecological preparation supplement level increased. In conclusion, supplementation of microecological preparation improved the growth performance of broilers.

Silage is widely used in ruminant production because of high nutritive value, low cost and not limited by the weather and season. During the process of making silage, there are refer to degradation, fermentation, so it is necessary to use additive to control these process. Silage additives play roles in silage preservation, promotion, improving the palatability in fermentation. Silage additives can be divided into: inhibition additives, catalytic additives, nutritional additives. This article provides an overview for the kinds, function and its effect of silage additives in recent years, as well as the development direction in the future.

Chromium is an essential trace element for animals. In recent years,domestic and foreign nutritionists have started a lot of research,especially in weaned piglets feeding areas,and have made a lot of money results.In this paper,organic chromium absorption,transport and excretion characteristics in vivo,and the biological function of organic chromium,including the glucose metabolism,lipid metabolism and nitrogen metabolism were recommended,and then introduced the effects of growth performance,anti-diarrhea,immune function and other aspects of in the feeding of piglets weaned pigs,as well as application prospect of in weaned piglets were summarized.

γ-aminobutyric acid (GABA) is a non-protein amino acid to play neural stabilization role in animal body, exists widely in the central nervous system, the peripheral nervous system and some endocrine cells of mammals. It is an important neural inhibitory neurotransmitter, which has a significant effect on improving animal intake, milk yield, survival percentage and stress response, reducing breathing rate, shortening estrous interval, and so on. This article delivers a brief summary on the preparation and physiological function of GABA and its research status in the livestock and poultry production.

In order to explore and establish a new method of isolation,culture,and identification of alpaca skin melanocyte in vitro for further studying to provide a suitable pigment deposition cell model. Take 1 to 3 years young alpacal skin,with three different enzymes (trypsin,trypsin-EDTA,Dispase Ⅱ) digestion alpaca skin,alpaca melanocyte were obtained by trypsin-EDTA digestion,placed into DMEM/F12 culture medium. Analyze melanocyte growth,cell yields and cells attached.The results showed Dispase Ⅱ group had a significant higher other groups (P＜0.01).In summary,alpaca melanocyte were obtained by Dispase Ⅱ digestion.

To investigate the effect of molybdenum on the lipid peroxidation injury and Smac protein expression of kidney in famale mice. Selected sixty 35-day-old female Kunming mice were randomly divided into 3 groups (control group, molybdenum groupⅠ, molybdenum groupⅡ). Three groups were treated with drinking water added with 0, 200, 400 mg/L molybdenum (Mo⁶⁺), respectively. On the 90th days of experiment, the SOD activity and MDA contends were measured, the expression of Smac protein were examined immunohistochemically in kidney tissue. The results showed that the SOD activity was lower in molybdenum group Ⅰthan that of the control group(P＜0.05), the SOD activity was lower significantly in molybdenum groupⅡthan that of the control group(P＜0.01);the MDA contends was higher in molybdenum groupⅡ than that of the control group in kidney tissue(P＜0.05); The expression of Smac of renal cortex was higher significantly in molybdenum group than that of the control group (P＜0.01). The results indicated that molybdenum may cause renal lipid peroxidation injury and promote expression of Smac protein in kidney tissue.

DNA methylation is the common base modification in the eukaryotic genome and is an important epigenetic mechanism. Methylation at the five-carbon of cytosine is a reversible process that can directly influence gene activity and the reaction is catalyzed by a family of DNA methyltransferases(DNMTs). DNA methylation is essential for normal mammals development and plays an important role in the affects a wide range of essential biological processes,and it includes silencing of transposable elements,inactivation of genes,maintenance of chromosomal integrity,X chromosome inactivation,and transcriptional regulation of a large number of genes and so on.

In the present study,four experiments were conducted to investigate the potential effects of tPA on bovine cumulus and oocytes during in vitro maturation (IVM) (0,8,16,24 h). The expressions of tPA were detected by relative Real-time RT-PCR experiments in bovine cumulus and oocytes both after 0,8,16,24 h of IVM and under different FSH concentrations after 16 h of IVM separately. Meanwhile,the degree of bovine cumulus cell expansion and the percentages of first polar body in oocyte were assessed respectively. TPA mRNA levels were higher in cumulus and oocytes at 16 h and 24 h than those at 0 h and 8 h of IVM significantly (P<0.05). Among those groups that under different FSH concentrations (0,0.01,0.1 and 1 IU/mL) after 16 h of IVM,tPA mRNA levels of cumulus was increased following the elevated FSH concentrations,as well as the cumulus expansion,tPA mRNA of cumulus cells in 1 IU/mL FSH group was significantly higher than others. The results indicated that the expression of tPA in bovine cumulus was regulated positively by FSH,tPA could facilitate the cumulus expansion during IVM. However,it needed to be further investigated that tPA expression might be involved in first polar body excrusion of bovine oocytes.

According to the bovine keratin 14 (K14) gene sequence designed the PCR primers,and acquired the 2834 bp gene sequence(GenBank accession:JQ063036) by the DNA of Inner Mongolia Cashmere goat. This region included 2631 bp promoter region and 203 bp the first exon of structural gene of goat K14 gene. Sequence aligenment and analysis,and study the polymorphism of K14 promoter. It was found that goat’s and human’s structure of K14 promoter were different,both only having three common transcription factor binding sites such as Sox-5,GATA-1,GATA-1/2 binding sites. However,with the cattle’s had a higher similarity,containing the Sox-5,SRY,CdxA,MyoD,MZF1,GATA-1/3,Nkx-2 binding sites etc.7 common transcription factor binding sites. And it was found that goat K14 promoter region had five unique transcription factor binding sites,such as deltaE,GATA-2,GATA-1,Sp-1,AML-1a binding sites. In addition,the single nucleotide polymorphism (SNP) of goat K14 promoter was investigated,including four SNPs. Among these two novel SNPs were located in Nkx-2 binding site(-2004—-1996 bp) or near the several bases of Nkx-2 binding site Nkx-2(-1590—-1583 bp).

The experimental material used Yunling goat oocytes from slaughterhouse,to study the effect of the oocytes vitrification. Using 20% EG+20% DMSO as a frozen solution and the cryloop for carrier to vitrify the GV and MⅡ stage oocytes in 20 s and 40 s vitrification time. The results showed that,GV oocytes morphologically normal rate,maturation rate and cleavage rate were very low. After maturation culture,the maturation rate and cleavage rate of the vitrification groups was significantly lower than the control group (P<0.01). MⅡ oocytes frozen was better,the rate of normal morphology of the toxicity test group and vitrification group were 91.1% and 83.3%,was significantly higher than the GV stage. After parthenogenetic activation,the cleavage rate,the toxicity test group and control group,were no significant differences(P>0.05). The vitrification group cleavage was significantly lower than the control group(P<0.05). The GV and MⅡ oocytes in each group were not significantly different in 20 s and 40 s vitrification time. According to the results it was the best to vitrify MⅡ oocytes in the cryopreservation,in order to improve the cleavage rate and blastocyst rate. The oocytes vitrification time did not affect oocyte viability and developmental potential in the 40 s inside.

In this study,we detected a novel single-nucleotide polymorphism of the PPAR-α gene in Chinese native cattle by screening for genetic variation of PPAR-α in 944 individuals of three Chinese cattle breeds,namely China Holstein,Bohai Black and Luxi Yellow,using PCR-RFLP and DNA sequencing techniques. The sequencing results indicated that there was one single nucleotide mutation (G to A) in the 44087 of the PPAR-α gene. Chi-square test indicated that 44087G>T polymorphic site in the PPAR-α gene didn’t meet Hardy-Weinberg equilibrium in Holstein and Luxi cattle(P<0.05);The genetic correlations between genotypes and heat shock response were obtained by the least square analysis,and the results showed that genetic polymorphisms significantly correlated with somatic cell scores (SCS),and milk productive traits. GA genotype in 44087G>A polymorphic site in PPAR-α gene was an excellent site,SCS of the individuals were significantly lower than GG genotype (P<0.05); cows with GA genotype had a significantly higher protein levels and milk yield in the hot environment than GG genotype (P<0.05),so GA genotype was resistive heat. The resulting analysis of the GA genotype might help to improve the performance of Chinese Holstein cows milk. In the process of artificial selection,the GA genotype individuals could reduce heat stress to cows harm,and at the same time was able to improve milk quality and yield.

This test using totle 9 head of cattles,which were 3 to 6 month old healthy and susceptible (IBRVand BVDV antigen negtive,antibody titer is less than or equal to 2),were divided into 3 groups,each group of 3 cows. The first group was injected with IBRV-LNM attenuated vaccine strain,one weeks later each animal was inoculated with BVDV-SM attenuated vaccine strain. The second group was only inoculated with BVDV-SM attenuated vaccine strain at the same time with the first group. The third group was the control group and inoculated with MDBK cell culture fluid. the determination of BVDV antibody titer post-vaccination every week until 28 days,and then challenged with BVDV-JL virulent strain. The results showed that the serum of bovine viral diarrhea virus antibody levels had no significant differences between the first and the second group, and observation after the challenge showed that the vaccine effectively protected calves from the challenge.This suggested that IBRV attenuated strain was not restrained BVDV attenuated vaccine virus in vivo.

The dynamics of viremia,ALV-J antibody response in yellow chickens and p27 antigen shedding in cloacal swabs were examined respectively after the 11-day-old yellow chicken embryos were inoculated with hemangioma related ALV-J SCAU-HN06 isolate via allantoic cavity. The results showed that viremia could be detected as early as 1 week post hatch,there was a viremia peak at 7 week,and the positive rate of viremia remained more than 80% continuously since 9 week. ALV-J antibody response could be detected as early as 6 week by ELISA,the positive rate of antibody was no more than 33.3% during the trial. The positive rate of p27 antigen in cloacal shedding rised quickly,reached peak at 3 week,then kept at high level. The study suggested that ALV-J isolate infection via egg inoculation could result in persistent viremia and immunotolerance. The study provided the basis for ALV-J control and eradication in yellow chickens.

The porcine EMCV GXLC strain was used to infect 4-week-old healthy BALB/c mice to evaluate its pathogenicity. After infection, the clinical signs were observed; the pathological changes were analyzed and the ratios of heart weight to body weight were recorded; the viral loads in heart, brain, spleen and serum were determined; the protein loads of IL-1β and TNF-α in serum and the mRNA expression levels of IL-1β, TNF-α and IL-6 in heart, brain and spleen were detected. The results showed that the infected mice displayed obvious manifestations, and began to die on 4 days post-infection (DPI), reaching the death peak from 5 to 7 DPI. The heart and brain of the infected mice showed apparent gross lesions and histopathological changes, of which the ratios of heart weight to body weight and the histopathological scores were significantly increased. A large number of viruses were detected in brain, heart, spleen and serum from 1 DPI up to 14 DPI. The protein loads of IL-1β and TNF-α in serum from the infected mice were significantly increased and the mRNA expression levels of IL-1β, TNF-α and IL-6 in heart, brain and spleen were significant up-regulation, with closely positive correlation in time with obvious manifestations, severe pathological lesions and death peak of the infected mice. The results indicated that porcine EMCV GXLC strain was highly pathogenic to mice and the proinflammatory cytokines IL-1β, TNF-α and IL-6 played important roles in the pathogenesis of EMCV.

Currently, multi-infections of bacterial and viral diseases affected China's pig industry seriously. In September 2011, large number of pigs from a pig farm of Yangjiang City, Guangdong Province have incidence and manifestations as hyperthermia, cough, decreased appetite, skin cyanosis, joint swelling and other clinic symptoms. The epidemiological investigation and laboratory diagnosis on disease samples. The multi-infections with highly pathogenic PRRS virus, porcine circovirus type 2, and Haemophilus parasuis was diagnosed by bacterial isolation,PCR, RT-PCR,etc, and corresponsive methods were applied to control this outbreak.

In order to prevent the gosling plague and the goose paramyxovirus disease, the JLDA strain of the gosling plague and the strain JLSY of the goose paramyxovirus were selected to produce the oil-emulsion inactivated vaccine against gosling plaque, goose paramyxovirus disease. Applied the PALL condensing technic to condense the virus, the vaccine was ensured that the antigen content was enough and the proportion was equilibrium. The 10^# white oil was selected as the adjuvant and the proportion of the oil and water was 1∶1, the ropy degree of the vaccine was low. The results showed that the immune effect was not lower than that of the corresponding vaccine, and indicated that the goose parvovirus and the goose paramyxovirus could not be interfered.The results were that the protection rate of the vaccine preserved for 15 months was lower than that of the vaccine preserved for 12 months and showed that the two combined vaccine could be preserved for at least 12 months at 2 to 8 ℃.

The pathogen were isolated and identified on feces of sick piglets and disease of the spleen, liver, lymph nodes, lung, kidney edema fluidin a pig farm in Hunan northwestern region. Susceptibility of 15 kinds antimicrobial drug was determined with the Kirby-Barer for isolated strains. The results showed piglets were infected with E. coli-based and Staphylococcus. Escherichia coli was sensitive to gentamicin, cephalosporins latter skin, Amikacin, tetracycline, cefoperazone sodium, to chloramphenicol, piperacillin, pioneer V, ceftriaxone, neomycin was intermediate, to carbenicillin, doxycycline, penicillin, ampicillin, erythromycin had a higher resistance. Staphylococcus was sensitive to pioneer V, Amikacin, to ceftriaxone was intermediate, on the other antibiotic was resistance. Which was 33.33% the rate of drug sensitivity, intermediate and resistance to E.coli. Which was 13.33% sensitive rate, intermediate rate was 6.67%, resistance rate was 80.00% to Staphylococcus.

Mastitis is a multiple factor disease,influenced by circumstance,pathogenic bacteria and animal condition,morbility rate of primiparity cow mastitis is much higher than the adult cows. As to the character of primiparity cow,the paper analyze several factors,which contains health supervision,application of nipple aquaseal,vaccine control,antepartum milk,control of fly,milk of mastitis cow,udder dropsy and synthetic manage,and intend to provide reference to clinical cure.

This test separate to 54 plants duck highly pathogenic Escherichia coli source by the bacteria isolation, culture characteristic observation and biochemical test and pathogenic test, epidemic materials come from the Yellow River delta regional scale meat duck intestines goods in 2011. The drug sensitivity test found that separation strains of several antibiotics exist multiple resistance, wherein, three drug resistance of Phytomycin, Ampicillin and Clindamycin reached more than 90%. Higher sensitivity of drugs have Amikacin, Cefotaxime, Ceftriaxone and so on. This test identify preliminarily 12 kinds of serum type exist through O serum antigen type classification, including the region superiority serotype of O78, O35, O2, O18 were 12 strains, 8 strains, 6 strains and 5 strains. This test provide the reference for understanding and grasp the duck source area the epidemic of Escherichia coli disease and further research and prevention and control the disease.

4 strains of gram negative bacilli were isolated from 7 portion materils colleted from some pig farms of Jinzhou. Haemophilus parasuis was finally diagnosised by isolated culture test, staining microscopy, biochemical tests, the test of V factor need, satellite phenomenon examination and PCR.The results of drug sensitivity test indicated that 4 strains of bacteria were sensitive to lincomycin, ciprofloxacin, doxycycline, cefotaxime,ofloxacin,and enrofloxacin and resistant to kanamycin, cotrinoxazole, clindamycin, chlortetracycline and tetracycline. 4 strains of bacteria showed different sensitivity to streptomycin.

In this article, the statu of provention and treatment, the role of vascular endothelial cell during the pathogenic of the chicken E.coli disease progress,the function of the traditional Chinese medicine on chicken colibacillosis, and the unique advantage of traditional Chinese medicine against E.coli were reviewed.

The present study was conducted to investigate the infection situation and prevailing characteristics of hepatitis E (HE) infection in swine herds in Guangdong. Antibodies of hepatitis E virus from 484 sera samples collected from Guangdong 2009 to 2011 were detected by double-antigen sandwich ELISA.Furthermore, strains of hepatitis E virus were isolated from 69 swine bile samples, in order to understand the genetic characteristics and evolution regularity of the virus. The results showed that the swine herds in Guangdong with a high antibody positive rate (71.9%) to HEV. Molecular epidemiology investigation showed that the epidemic strains in Guangdong was genotype Ⅳwith 71.0%(49/69)positive rate.

To understand the intestinal flora composition of four types of common freshwater fish in Dongping Lake of Shandong province, aerobic or facultative anaerobic bacteria of intestinal flora in Ctenopharyngodomi dellus, Hypophthalmichthys molitrix, Cyprinus carpio haematopterus and Carassius auratus were isolated and identified, with the quantity and composition of intestinal flora being analyzed. The results showed that in this study Hafnia, Xenorhabdus, Ameromonas, Citrobater, Bacillus, and Strooptococus were common to each type of fish, and Cyprinus carpio haematopterus and Carassius auratus contained appropriate quantity of intestinal flora with little difference in genus quantity.

Etiological diagnosis were done to the dead broiler from one farm which experienced the epidemic in this experiment. The isolated bacteria were identified by methods of pathogenic separation, biochemical tests, animal experiments, serotype identification, PCR amplification and so on. As a result, the mixed infections of E.coli and Enterococcus faecalis were identified. Further more, drug susceptibility tests were taken according to the isolated bacteria and the high sensitivity antibiotics against E.coli named amikacin and gentamycin were selected, while only some fluoroquinolones showed moderately sensitive against Enterococcus faecalis among the 21 antibiotics. Then amikacin, gentamycin and enrofloxacin were used for the treatment of broiler, which showed quick effects on controlling the death, and greatly reduced the economic losses caused by the epidemic.

With the increase of public attention to food safety, the harmful substance in milk had attracted much attention of consumer. Although the standard method to detect antibiotics in milk had been estabolished in China, the operation was laborious and inconvenient, besides, they can’t solve the new situation appeared in recent years. This article reviewed the research new progress of detection method of antibiotics in milk, aimed to supply some reference to the further research in this area.

Campylobacter is a main bacterial source of human acute gastroenteritis, many animals are natural host of Campylobacter and serves as major reservoirs for this pathogenic organism. As a foodborne pathogen, Campylobacter is transmitted to humans via food chain. Antimicrobial agents have been widely used for growth promotion and disease control. Thus, agricultural use of antibiotics poses a risk for selecting antibiotic resistant pathogens that can be potentially transmitted to humans and may compromise clinical treatment. In this article, prevalence and antimicrobial resistance data of China and abroad was introduced briefly.

A PCR kit for detection bovine tuberculosis IS6110 gene was developed based on PCR principle with designing a pair of primer from GenBank. A specific band (317 bp) was detected with the PCR kit. By sensitivity analysis,a minimum of 1.025 pg pathogen DNA was detected, and pathogens of control groups,such as Pseudo tuberculosis,Actnobacillus,Escherichia coli,Pastueurella,Salmonella,Staphylococcus aureus,Streptococci showed nagative.The kit could be stored at －20 ℃ for a year and having a repeating performance. With the PCR kit, 24 cases was diagnosed and the result was similar to tuberculin test. The PCR kit can be a good method for clinical diagnosis of bovine tuberculosis with rapid, sensitivity and specificity.

To investigate the floor rearing with or without outdoor access on growth performance and meat quality of Jinghai yellow chicken. Eighty day-old Jinghai yellow chicken were randomly divided into two groups, the floor rearing with outdoor access and the floor rearing without outdoor access, 40 chicken for each group (20 cocks and 20 hens). The two groups were fed with basal diets. The results showed that the floor rearing without outdoor access could improve growth performance of broilers; the floor rearing with outdoor access could reduce abdominal fat rate and improve leg muscle percentage extremely;the floor rearing with outdoor access could significantly increase shearing force and reduce tenderness ,tend to improve pH value, meat color, and water keep ratio.

The lamb milk replacer is signality in early weaned lambs and lamb industrial production. The current situation that the mutton are imbalance between supply and demand,and prices are too high in Xinjiang. Using the lamb milk replacer in the lamb industry production,developing high-quality lamb meat and fat lamb production,constructing intensive,scale and industrialization of the sheep industry,what is an effective way to resolve this contradiction.

The present study was conducted to study the effects of ventilating and spraying on the gain performance, immune function and incretion of beef cattle in north China from the point of animal welfare. Twenty-eight Holstein bull calves with similar body weight and age were randomly divided into two groups with two reduplicates in each group. One was the experimental group with the device of fan and water sprayer, and the other was the control group.The experiment lasted for 28 d. The results showed that the environmental state in animal house was significantly improved by ventilating and spraying, and feed intake was significantly increased (P<0.05). In addition, the concentrations of ACTH and CORT in serum were significantly reduced (P<0.01), and the concentrations of GH, IgG and IgM in serum were significantly increased compared with the contral group in every test stage. Overall, gain performance and immune function were ensured and animal welfare was improved by ventilating and spraying.